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Watermelon Citrulline: How Much Is in the Fruit?
Watermelon citrulline is the amino acid that gives the fruit its best-known nutrient claim: about 365 mg in one cup of diced seedless watermelon. Studies of L-citrulline for blood pressure used 3 to 9 g a day. Melonex lists no watermelon; its citrulline line is L-Citrulline DL-Malate, at most 500 mg per capsule.
Written by the Melonex numbers deskUpdated · 4 min read
01The basics
What is watermelon citrulline?
Watermelon citrulline is the free amino acid L-citrulline found in watermelon flesh and rind. The name citrulline comes from the fruit's Latin name, Citrullus.
Watermelon is the best-known food source. The NIH Office of Dietary Supplements puts one cup of diced seedless watermelon at about 365 mg (NIH ODS, citrulline in watermelon).
Amounts differ by variety and ripeness, so treat that figure as a ballpark.
Our label has no watermelon, melon extract or fruit powder on it. The citrulline in Melonex is a salt form listed as L-Citrulline DL-Malate.
02Fruit math
How much watermelon equals a studied dose?
A 3 g dose of citrulline equals about 8 cups of diced watermelon, using the 365 mg a cup figure. A 9 g dose equals about 25 cups.
Trials of L-citrulline for blood pressure used 3 to 9 g a day as a supplement, not fruit (Avicenna J Phytomed 2019, L-citrulline and BP meta-analysis). This is simple division, not a feeding study.
| Source | Citrulline | Cups to match |
|---|---|---|
| 1 cup diced watermelon | about 365 mg | 1 |
| Low trial dose | 3,000 mg | about 8 |
| High trial dose | 9,000 mg | about 25 |
The fruit also brings sugar, water and potassium. Cups are a thought experiment, not advice. Eating that much watermelon every day is not what any of these studies tested.
03One capsule
How does a Melonex capsule compare with a cup?
One Melonex capsule holds at most 500 mg of the citrulline line, which includes the malate part. At NIH's roughly 57% ratio, that is under 285 mg of citrulline, less than one cup of fruit.
Federal rules list blend lines by weight, so the first line can weigh at most 500 mg (21 CFR 101.36 (proprietary blends)). Melonex prints no ratio, so the 57% figure applies only if it follows the usual one for citrulline malate (NIH ODS, Supplements for Exercise).
An even split of the blend is about 167 mg per line, so the real citrulline may be lower still. The drawing shows the even split for scale.
Drawing, not data: an even split shown for scale. The label prints only the 500 mg total.
- L-citrulline DL-malateeven split ~167 mg · ceiling ≤500 mg
- L-arginine AKGeven split ~167 mg · ceiling ≤250 mg
- L-arginine HCleven split ~167 mg · ceiling ≤167 mg
Also in the capsule (no amounts printed)
- Hydroxypropyl methylcelluloseThe vegetable capsule shell (a plant-cellulose material)
- Microcrystalline celluloseA plant-fiber filler that bulks out the powder
- Magnesium stearateA flow aid that stops powder sticking to machines
No trial tested Melonex. The studies above used grams of plain citrulline, a different scale from a 500 mg blend.
04Food or capsule
Is citrulline from food the same as from a capsule?
The amino acid is the same molecule, but food and a malate salt differ in amount, packaging and what comes with them.
Watermelon gives citrulline in a cup of fruit with water, sugar and fiber. A capsule gives a measured blend with a vegetable shell and two fillers.
Fruit
Amount varies by variety and ripeness. No label, no standard dose.
Capsule
Weight is fixed per capsule, yet single amounts stay hidden inside the blend.
Citrulline may interact with blood-pressure drugs, nitrates and erectile-dysfunction drugs (WebMD, L-citrulline). Keep taking prescribed medicine and tell your doctor about any supplement.
05Your pick
Should you eat watermelon or take capsules?
Eat watermelon because you like it; it needs no label check. Choose a capsule only after reading the label and talking to your doctor.
Fruit and capsule solve different problems. Fruit is food. A capsule is a product with a 500 mg blend and a 60-day bottle at one a day.
See every ingredient on the Melonex label and the line-by-line limits in the citrulline page. For the dose side, read the dose post.
Prices listed on the seller's order page; confirm at checkout. The 2-bottle kit costs $158, with $9.99 shipping. Ask your doctor about your medicines first. 60-day money-back guarantee per the seller.
Melonex is not a treatment; it is a dietary supplement. Ask your doctor or pharmacist first if you take blood-pressure medicine, nitrates for chest pain, an erectile-dysfunction drug such as sildenafil or tadalafil, a potassium-sparing diuretic (amiloride, spironolactone, triamterene), a blood thinner, or diabetes medicine, or if you have had a recent heart attack. Arginine and citrulline can add to these. Keep taking prescribed medicine. See side effects and interactions.
06FAQ
Melonex questions people ask
How much citrulline is in a cup of watermelon?
About 365 mg in one cup of diced seedless watermelon, per the NIH Office of Dietary Supplements. Values vary with variety and ripeness.
Can you get 3 g of citrulline from watermelon?
Only with a lot of fruit: about 8 cups of diced watermelon, at 365 mg a cup. That is a division sum, not a trial. The studied 3 to 9 g doses were supplements, so fruit cannot be assumed to act the same way.
Is there watermelon in Melonex?
No. The label lists L-Citrulline DL-Malate, two L-arginine forms, a vegetable capsule shell and two fillers. No watermelon, melon extract or fruit powder is named, so the citrulline is not sourced from the fruit by anything the label says.
Is watermelon citrulline the same as citrulline malate?
Citrulline is the same amino acid. Citrulline malate pairs it with malate, and NIH puts it near 57% citrulline by weight. The weight of a capsule line therefore overstates the citrulline it holds.
07Who wrote this
Written and reviewed by
Pages built from the label, the seller's materials and linked NIH, FDA, CDC, AHA, FTC and peer-reviewed sources.
Last updated . Read how we write and how we check reviews. This website is run by Melonexheart, which describes itself as a U.S. authorized Melonex merchant. It is not the manufacturer or the label's distributor, and we cannot independently verify the 'authorized' status. We are paid when you buy through our order links.
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